The statistical properties of sib-pair and variance-components linkage methods were compared using the nuclear family data from problem 2 of the Genetic Analysis Workshop 10. Overall, the power to detect linkage was not high for either method. The variance-components method had better power for the detection of linkage, particularly when covariates were included in the model. Type I error rates were similar to nominal error rates for both methods. - Computer simulation, genometrics, linkage analysis, variance-components, sib-pair